Hoarding disorder (HD) has been recently added as a separate diagnostic category in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders. HD is a common and disabling disorder, with an estimated prevalence in the general population of 2–6%. Although evidence suggests that the onset of hoarding symptoms is usually during childhood and adolescence (youth), relatively little is known about HD in this population. The present article is a selective review of emerging literature on the clinical features of hoarding in youth.

The interpretations of relevant interfaces (i.e. the surface and bed) in radar sounding datasets over glaciers and ice sheets are primary boundary conditions in a variety of climate studies and particularly subglacial water routing models. It is therefore necessary to ensure these interpretations are consistent and not affected by cross-track clutter. For the surface interface, interferometry and a family of methods relying on digital elevation models have been used to successfully discriminate cross-track surface clutter. Here we present how interferometry can be applied to the problem of basal clutter from cross-track bed topography. Our approach is based on a comparison of the differential phases of ambiguous reflectors that may represent bed clutter and the differential phase of a reflector in an adjacent area that appears unaffected by basal clutter. The reflector yielding the smallest interferometric phase difference relative to the unambiguous bed reflector is considered to represent its consistent continuation. We successfully demonstrate our approach using 60 MHz center frequency MARFA data collected over Devon Ice Cap in the Canadian Arctic. Finally, we investigate the effects of clutter-affected and interferometry-corrected bed interpretations on ice layer thickness estimates, basal hydraulic head gradients and the potential extent of inferred subglacial water bodies.

Treatment of compulsive hoarding has rarely been described in the literature, apart from standard treatments for obsessive compulsive disorder of which hoarding is thought to be a subset. This paper presents preliminary findings from seven patients treated with cognitive and behavioral interventions derived from Frost and Hartl's (1996) theoretical model of hoarding. Six clients attended 15 group treatment sessions over 20 weeks plus individual home treatment sessions and one client received 20 weekly-sessions of individual treatment only. After 20 weeks, treatment resulted in noticeable improvement in several hoarding symptoms for five of the seven patients, especially reduction in excessive acquisition of possessions, although problems with clutter persisted. Three of four clients who continued in treatment for approximately 1 year showed substantial further improvement, although none felt entirely recovered. Findings are discussed in light of the model of hoarding and possible modifications to treatment to enhance motivation and benefits.

We present some general results related to first-passage percolation. These results involve families of random variables arranged in independent subfamilies. Applications are given to the study of random networks and to first-passage percolation.

Some recent results of Oxley and Welsh (1979) and McDiarmid (1981) concerning Bernoulli percolation on clutters are generalized. Our results allow to consider quantitative aspects of percolation on graphs and clutters.

I introduce some useful general results concerning clutter percolation and families of binary random variables arranged in independent subfamilies, and give several applications to the study of random graphs and digraphs.